package com.hmdp.utils;

import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.format.annotation.DateTimeFormat;
import org.springframework.stereotype.Component;

import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

/**
 * @Author Luming
 * @Date 2024/4/22 21:52
 * @Description: 全局ID生成工具类
 */
@Component
public class RedisIdWorker {
    
    /**
     * 开始时间戳
     */
    private static final long BEGIN_TIMESTAMP = 1713744000L;
    /**
     * 序列号的位数
     */
    private static final int COUNT_BITS = 32;
    
    private StringRedisTemplate stringRedisTemplate;
    
    public RedisIdWorker(StringRedisTemplate stringRedisTemplate) {
        this.stringRedisTemplate = stringRedisTemplate;
    }
    
    public long nextId(String keyPrefix) {
        //1.生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);
        long timestamp = nowSecond - BEGIN_TIMESTAMP;
        //2.生成序列号
        //2.1获取当前日期，精确到天
        String nowDate = now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        //2.2自增长
        Long count = stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + nowDate);
        //3.拼接并返回
        
        return timestamp << COUNT_BITS | count;
    }
    
}
